A Dump and Run is an act where a man, pulls out (from the anus, and or vagina) with his penis partway through intercourse on the night he plans to end a relationship. At this point he should have a doozer, also known as a load of poop, ready to exit his rectum. He then pushes her down, poops on her chest, backhands the girl, and runs out her front door streaking, laughing hysterically.
Also, see Pump and Run
Man, that damn girl annoyed me so I gave her a dump and run; I can go to the party this weekend now.